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TO ALL WHOM IT MAY CONCERN:

Be it known that I, HENRY CHATFIELD, of Wolcottville, in the county of Litchfield, and State of Connecticut, have invented Improvements in Hoisting Apparatus; and I do hereby declarethat thevfollowing is a full and exact description thereof, reference being had to the accompanying drawings, making part of this' specification- Figure 1 being a front elevation of a hoisting apparatus provided with my improvements,

Figure 2 a vertical sectionof a position thereof, 'in a plane indicated by the line :c x, tig. l,

Figui-e3 a transverse horizontal section, in a plane indicated bythe line y y, iig. 1.

Like letters designate corresponding parts in all of the iiguiies.

My improvement-sare applied to a power-winding apparatus for raising heavyweights, using two belts, one open and the other crossed, with fast and loose pulleys for reversing the motions to raise or lower the weights.

Let A represent the frame or ways of the apparatus, and N' a guide-frame, ascending and descending in the ways, the'weight being secured thereto. The frame N is suspended aud raised by arope or chain, L, which is wound upon av horizontal shaft or drum, D. The driving-pulley may be upon this shaft, for raising lighter weights, but, for raising heavy weights or articles, gearing B C may be employed to speed down the motion from a separate pulley-shaft, c, and thereby increase the power. This speeding down may be carried to any extent, there being intermediate gearing, ifnecessary.

The two loose pulleys being represented by`a In, and the fast pulley by c, between the looseA pulleys', the crossed belt m and open belt n are situated such `a distance apart that when one is' on thc fast pulley the other is on its respectiveloose pulley. Hence, one must pass off from'the fast pulley before the other begins to pass upon it, and there is an interval, therefore, when the winding-shaft is not sustained by the belt, and, to insure safety, some secure means must be adopted to sustain the weight during that'interim between the actions of the belts.

My improvement vin this part of the apparatus consists in the method of operating the brake Cr,whieh holds against the fast pulley c'by the movement of the sliding belt-shipper H, through means of a pair of toggle-arms, I I, that connect the said belt-shipper with the brake-lever F. This brake-lever is pivoted at one end, f, and one toggle-arm, I, is pivoted to theiother vibratory end of the lever, as at g. The twotoggles are jointed together at z', and the upper toggle is secured rigidly to the belt-shipper H by passing it transversely through the same, and securing it by a screw-thread thereon and nuts j j, substantially as shown in g. l'. The length of the toggle-arms and the pressure of the brake are adjusted 'by these nuts, or the equivalent thereof. The toggle-arms are so arranged that, when either belt is onl the fast pulley e, they will not be Ain line with cach other, as shown by black lines in figli, and hence thcbrake Gwill be drawn. away from thc pulley and nothinder its free motion. But, when the toggle-arms are brought into line with each other, as shown by red lines in the -same figure, they willjforce the brake powerfully against the pulley, and this takes place just when thc belts are off of the fast pulley. This movement is automatic and sure, and, if all parts'are strong and firm, itrcannot fail to secure the safe suspension of the weight. I have found it to be perfectly reliable in practice with the heaviest weights.

But, to secure the apparatus against accident, even if the safety-brake G should fail, Ihave added adevice to prevent the weight from falling, even if the suspension should fail. For this purpose the guide-frame N, to which the weight is attached, and which` is suspended hy the winding-rope or chain L, is provided with a pair of strong dogs or catches, s s, which act in eonnection'with racks or sustaining notches pp along both sides of the ways A A, substantially as s hown in thc drawings. The Vdogs arc pivotedatt t to a central cross-har, r, through which passes. a suspension-bolt, M, forming the connection between the rope L and the guide-frame N. This bolt also extends down through the head of the said guide-frame and through a spring, o, underneath the same. It has a sliding movement in its place, and all the parts are so arranged that, when a weight' or article is suspended by the frame, the springe is compressed and the bolt is raised to its highest position, and this draws the dogs in, so that they do not touch the rack-teeth pp, and so the guide-frame slides freely up and down in the ways A A, all as indicated by lblack lines, fig. 1. But should anything give way above, so thatth'e weight should no longer be suspended thereby, the spring o would draw the bolt M downward, and thereby force the sliding-dogs s s out, so as to engage with the notches of the racks p p, and thereby prevent the descent of the guide-frame N, and the consequent falling of the weight, all as indicated by red lines in g.'1. Guide-straps u u are employed to keep the dogs s s in place, and hold them' rmly to the head of the guide-frame N.

What I claim as my invention, and desire to secure by Letters Patent, is

In'combination with a hoisting machine, the toggle-arms II, arranged and operatingin connection with the `beit-shipper H, brake-lever F, and brake G, substantially as and for the purpose herein specified.

The nbove specification of my improvement in hoisting apparatussigned by me this 2d day of February, 1867.

HENRY CHATFIELD. v

Witnesses:

H. S. BARBOUR, JNO. H. BAnBoUR. 

